heirloom vs belongings

heirloom and belongings both are nouns.

Word	Noun	Adjective	Verb	Adverb
heirloom	Yes	No	No	No
belongings	Yes	No	No	No

As nouns, belongings is a hypernym of heirloom; that is, belongings is a word with a broader meaning than heirloom:

heirloom: (law) any property that is considered by law or custom as inseparable from an inheritance is inherited with that inheritance
belongings: something owned; any tangible or intangible possession that is owned by someone

Other hypernyms of heirloom include holding, property.

heirloom (noun)	belongings (noun)
something that has been in a family for generations	something owned; any tangible or intangible possession that is owned by someone
(law) any property that is considered by law or custom as inseparable from an inheritance is inherited with that inheritance